Subarachnoid hemorrhage caused by ruptured dissecting aneurysm arising from the extracranial distal posterior inferior cerebellar artery--case report.
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A 50-year-old man presented with a dissecting aneurysm arising from the extracranial portion of the right posterior inferior cerebellar artery (PICA) causing subarachnoid hemorrhage (SAH) and manifesting as sudden onset of disturbed consciousness. Computed tomography showed SAH with ventricular reflux predominantly in the posterior fossa. Angiography revealed a fusiform aneurysm of the right PICA originating extracranially from the right vertebral artery. The aneurysm was isolated and excised. Histological examination showed dissection of the aneurysm wall. Dissecting aneurysm arising from the extracranial portion of the PICA is extremely rare. (+info)
Clinical significance of cerebrospinal fluid tap test and magnetic resonance imaging/computed tomography findings of tight high convexity in patients with possible idiopathic normal pressure hydrocephalus.
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Idiopathic normal pressure hydrocephalus (iNPH) is a treatable syndrome with a classical triad of symptoms. The Japanese iNPH guidelines indicate that the cerebrospinal fluid (CSF) tap test and tight high-convexity on magnetic resonance (MR) imaging are important for the diagnosis. The relationships between the effectiveness of CSF shunt surgery in possible iNPH patients, the tap test result, and the MR imaging/computed tomography (CT) findings of tight high-convexity were evaluated in 88 possible iNPH patients (mean age 75 years) with one or more of the classical triad of symptoms, and mild to moderate ventricular dilation. All patients underwent the tap test in the outpatient clinic, and patients and caregivers assessed the clinical changes during one week. The tap test was positive in 47 patients and negative in 41 patients. Surgery was performed in 19 patients with positive tap test, and was effective in 17 patients. Although the findings were inconsistent in some patients, the result of the tap test was found to be highly correlated with the MR imaging/CT finding of tight high-convexity (p < 0.0001), confirming that both these diagnostic tests are promising predictors of shunt effectiveness. (+info)
Rosette-forming glioneuronal tumor of the fourth ventricle--case report.
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Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a rare tumor included as a novel glioneuronal neoplasm in the 2007 World Health Organization classification of brain tumors. A 15-year-old female patient presented with RGNT of the fourth ventricle manifesting as headache persisting for one month. Magnetic resonance imaging disclosed a nonenhanced solid mass in the fourth ventricle and vermis. The tumor was gross totally resected. Histological examination revealed biphasic neurocytic and glial architecture. The neurocytic component consisted of uniform neurocytes forming neurocytic rosettes and perivascular pseudorosettes. Only 31 cases of RGNT have been reported. RGNT of the fourth ventricle should be considered in the differential diagnosis of infratentorial lesions in young adults. The prognosis is benign, but relatively aggressive behaviors such as tumor growth, recurrence, and acute deterioration due to intratumoral hemorrhaging can occur. Surgical resection requires care to prevent major surgical morbidities associated with lesions invading the cerebellum or brainstem. (+info)
Efficacy and safety of key hole craniotomy for the evacuation of spontaneous cerebellar hemorrhage.
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The efficacy and safety of cerebellar hemorrhage evacuation by key hole craniotomy and the importance of thorough evacuation and irrigation of the hematoma in the fourth ventricle to resolve obstructive hydrocephalus were assessed in 23 patients with spontaneous cerebellar hemorrhage (SCH) greater than 3 cm or with brainstem compression and hydrocephalus. A 5-cm elongated S-shaped scalp incision was made, and a 3-cm key hole craniotomy was performed over a cerebellar convexity area. The hematoma was immediately evacuated through a small corticotomy. The hematoma in the fourth ventricle was gently removed through the hematoma cavity, followed by thorough saline irrigation to release obstructive hydrocephalus. Patients classified retrospectively into favorable and poor outcome groups using the Glasgow Outcome Scale (GOS) scores of 4-5 vs. 1-3 showed significant differences with respect to the preoperative Glasgow Coma Scale, hematoma size and volume, and brainstem compression. Only 2 of the 23 patients required ventricular drainage and no postoperative complications were recorded. Patients treated by experienced and inexperienced surgeons showed no significant differences in the hematoma evacuation rate, postoperative GOS, and interval from skin incision to start of hematoma evacuation. Our simplified method of key hole craniotomy to treat SCH was less invasive but easy to perform, as even inexperienced neurosurgeons could obtain good surgical results. Thorough cleaning of the fourth ventricle minimized the necessity for ventricular drainage. (+info)
Ependymal alterations in sudden intrauterine unexplained death and sudden infant death syndrome: possible primary consequence of prenatal exposure to cigarette smoking.
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Microcystic meningioma of the fourth ventricle in a dog.
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A 5-year-old female cross-breed dog was presented with a 1-month history of progressive changes in the posture of the head and in the gait. At neurological examination the dog showed a central vestibular syndrome lateralized to the left. MRI showed a space occupying lesion within the fourth ventricle, characterized by iso- to hypointensity in T1 and hyperintensity in T2 with a heterogeneous contrast uptake. Histologically, a neoplasia composed of meningothelial cells forming compact whorls with slight atypia, and stellate cells delimitating microcysts containing eosinophilic fluid was observed. Neoplastic cells were positive for vimentin and negative for GFAP and FVIII. A diagnosis of intraventricular microcystic meningioma was achieved. Intraventricular meningiomas in dogs are rarely encountered and reports of meningiomas within the fourth ventricle have not yet been described. Although choroid plexus tumor is the most frequent neoplasia localized in the fourth ventricle, intraventricular meningioma should be included in the differential diagnoses. (+info)